Power transmitting mechanism



Dec. 30, 1941. E. s. LARsoN POWER- TRANSMITTING MECHANISM Original FiledMay 18, 1938 INVENTOR.

EDWARD s. LARsoN 'A ORNEY.

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Patented Dec. 30, 1941 POWER TRANSMITTING RIECHANISM Edward S. Larson,Chicago, Ill., assignor to Teletype Corporation, Chicago, Ill., acorporation of Delaware Original application May 18, 1938, Serial No.

Divided and this application December 30, 1939, Serial No. 311,712.

2 Claims.

This invention relates to power transmitting mechanisms and particularlyto roller bearing clutch mechanisms.

This application is a division oi copending application, Serial No.208,761, filed May 19, 1938, by E. S. Larson.

An object of the invention resides in an improved and simplified methodof assembling a roller bearing grip clutch.

The invention features the use of a spider for simplifying the assemblyof a roller bearing clutch mechanism, the fingers of the spiderreceiving the rollers and enabling the compression of springs for theindividual rollers by a single operation, whereby the roller assemblymay be worked into a ring member as a unit without necessitatingmanipulation of the rollers individually. The spider becomes a permanentpart of the assembly and serves as a retainer for the rollers.

The hereinbeiore identified copending application, and also a copendingapplication, Serial No. 193,642, led March 3, 1938, by Albert I-l.Reiber, discloses printing telegraph apparatus with the reference towhich the present invention is possessed of particular utility. Includedin the printing telegraph apparatus according to the copendingapplications is a main operating cam assembly which is driven by acontinuously rotatable shaft through a spring loaded jaw clutch capableof driving in one direction only. The cam assembly has secured theretothe inner element of a roller bearing grip clutch, the outer element ofwhich is a ring gear which is secured to the driving gear for the mainoperating shaft.

Roller bearing members are urged by compression springs into grippingengagement with the inner and outer members of the roller bearing gripclutch, the purpose of the assembly being to limit the speed of rotationof the main operating cam assembly to that of its driving shaft shouldit tend to accelerate under conditions of negative load. The rollerbearing grip clutch is arranged in compact relation to the main camassembly, which necessitates placement oi the roller bearingssubstantially in proper position with respect to the inner member withthe compression springs interposed between the inner member and therollers, whereupon the inner member and rollers are worked into positionin the outer member as a unit.

In order to simplify the assembly oi the roller bearing clutch mechanismand obviate the individual handling of the rollers during insertion intothe outer member, a method of assembly has beendeveloped which involvesthe use of a spider having lingers for receiving the rollers. The spideris supported by the cam assembly above the inner roller bearing clutchmember and is freely rotatable upon the cam assembly but it not movableaxially thereof. After the compression springs have been placed insockets in the inner clutch member and the rollers have been placed uponthe fingers of the spider, the spider may be rotated relative to theinner clutch member in the direction to compress the springs, wherebythe rollers are worked in close to the surface of the inner clutchmember and are prevented from being thrust outwardly by the compressionsprings. The compression springs exert a frictional retaining force uponthe rollers and prevent them from falling from the depending ngers. Theassembled inner clutch member, spider, and rollers may then be insertedinto the outer member of the roller bearing clutch and the spider servesas a permanent retainer for the rollers.

For a complete understanding ci the invention, reference may be had tothe following detailed description to be interpreted in the light of theaccompanying drawing, wherein Fig. 1 is a perspective view to illustratethe method of assembling the roller bearing grip clutch, showing thesubassembly of inner clutch members, retaining spider, and rollers aboutto be inserted into the outer clutch member;

Fig. 2 is a perspective view partly in section showing the completelyassembled roller bearing grip clutch; and

Fig. 3 is a detail view of the roller bearing clutch mechanism.

Referring now to the drawing, the reference numeral II designates ashaft to which hub I2 is pinned by pin I3. Hub I2 has secured thereto bymeans of screws I4 a gear Iii which may mesh with a continuously drivengear (not shown) whereby continuous rotation may be imparted through hubI2 to shaft II. A gear I1 for imparting rotation to another shaft, asfully disclosed in the hereinbefore identined copending application, issecured to gear I6 by means of screws I8.

A sleeve I9 has secured thereto a cam assembly sleeve 2l whch may havesecured thereto one or more function performing cams 22. Rotation may beimparted to sleeve I9 from shaft II through a undirectionally operablepositive clutch mechanism to be described later.

The sleeve I9, to which the cam assembly sleeve 2l is secured, isthreaded at its lower end vand the inner member 23 of a roller bearinggrip clutch is threadedly secured to the lower end of sleeve 2|. Innerclutch member 23 fits into the central aperture of gear I1 and isretained in close proximity to the hub I 2 of gear I6 as shown in Fig.2. Inner clutch member 23 has a plurality of substantially right anglednotches cut in the periphery thereof, the faces defining these notchesbeing of unequal length, the shorter of the two faces of each notch,designated by the reference numeral 24, extending substantially radiallyof the member 23. The angularly disposed faces of the notches and theadjacent arcuate inner surface of ring gear I1 define recesses that aregenerally triangular, being bounded by two plane surfaces and a curvedsurface. Each of the short faces 24 of the notches in member 23 isrecessed to receive and support one end of a compression spring 26. Anaxially drilled roller bearing 21 is disposed in each of the generallytriangular recesses, and the compression spring 26 tends to wedge theroller bearing between the long face of the notch and the arcuateinternal surface of ring gear I1.

The lower end of cam sleeve 2| is undercut to lprovide a shoulder 28against which a retainer ring 29 is placed before member 23 is securedto sleeve I9. Retainer ring 29 fits loosely on the undercut portion ofsleeve 2| and is not clamped in place but is free to rotate. Ring 29serves as a partial cover for rollers 21 and prevents them from escapingfrom their respective recesses in the event that a printing telegraphmechanism, or other apparatus in which the assembly is contained, isinverted, lsuch as, for example', during packing or shipping. Ring 29has an even more important function which will now be described.

Since roller bearings 21 cannot be inserted into their recesses aftermember 23 has been placed in position in ring gear I1, the retainer ring29 preventing this, it is necessary to fit member 23 and rollers 21 intoposition in ring gear I1 at the same time. Spring 26 tend to complicatethe bringing of the member 23 and the rollers 21 into final positiontogether, by thrusting the rollers 21 out of the position in which theymust be held in order to be inserted with member 23 into ring gear I1.The insertion of rollers 21 and member 23 has been simplified byproviding ring 29 with depending fingers 3| so that ring 29 may beemployed as an implement for locating rollers 21 well into their notchesin member 23, and for holding them in such positions in opposition totheir springs 26 while the subassembly is being inserted into ring gearI1. The rollers 21 are provided with axial bores of sufficient size thatthe rollers may fit loosely on depending fingers 3| of ring 29.

When it is desired to fit the subassembly comprising clutch sleeve 2|,its supporting sleeve |9, inner clutch member 23, and retaining ring 29into final position with inner clutch member 23 seated inside ring gearI1, a roller 21 is placed upon each of the fingers 3| of ring 29. Aseach .of the rollers 21 is placed upon its finger3l, its compress-ionspring 26 moves it away from the surface which contains the springsocket. The roller in being thus moved may impart counterclockwiserotation to ring 29 until nger 3| has moved as near to the long surfaceof the notch in member 23 as the thickness of the wall of roller 21 willpermit. Thereafter, spring 26 in the ring gear I1.

will frictionally engage the exterior of roller 21 and will cause it tobe gripped between nnger 3| and the long face of the notch in member 23,so that the roller will not drop from finger 3| while the other rollersare being placed on their respective fingers, nor while the subassemblyis being fitted into ring gear I1. After all of the rollers 21 have beenplaced upon the fingers 3|, ring 29 may be rotated in a clockwisedirection to compress springs 26 to a considerable extent, thus bringingthe rollers 21 as close as possible to the radial faces 24 of thenotches in inner clutch member 23 at which point the recess which willbe formed when member 23 is lowered into bring gear I1 will be ofgreatest width. Rollers 21 do not need to be held nor manipulatedindividually, as ring 29 imparts to all of them the desired movementtoward radial faces 24 of the notches. With rollers 21 held Well withinthe confines of the notches in member 23 by ring 29, the subassembly maybe lowered into ring gear I1 after which the hold upon ring 29 may bereleased, thus permitting springs 26 to move rollers 21 into frictionalengagement with the long faces of the notches and with the internalsurface of ring gear I1, ring 29 rotating freely to permit this movementof rollers 21.

The positioning of rollers 21 so that they will enter ring gear I1readily will be simplified if rollers 21 are caused to seek continuousengagement with the long faces of the notches in member 23. This may beaccomplished as shown in Fig. 3, by disposing the sockets or recessesfor -springs 26 so that the axes of the springs shall be outside theplane in which the axes of the rollers 21 move as the'rollers move incontact with the long faces of the notches.v It may also be desirable toproportion retainer ring 29 so that its fingers 3| are always inside theaxes of springs 26. The fingers may thus form fulcrums about whichsprings 26 may rock rollers 21 into engagement with the long faces ofthe notches, but whether or not the fingers form fulcrums for therollers, the forces exerted by the springs 26 upon the rollers 21 havecomponents which tend to keep the rollers in engagement with the longfaces of the notches in member 23. The rollers 21 are thus forcedinwardly sufficiently so that there will be no interference when theroller subassembly is fitted into ring gear I1.

Further simplification of the insertion of the subassembly comprisinginner clutch member 23, rollers 21, and ring 29 into ring gear I1 may beafforded by providing clearance recesses 32 Recesses 32 are cutpartially into the inner surface of ring gear I1 and partially into theupper face thereof, thus providing inwardly sloping cam surfaces. Shouldthere be any tendency of springs 26 to thrust rollers 21 outwardlyduring insertion of the subassembly into ring gear I1, the sloping camsurfaces will guide the rollers 21 down into the interior of ring gearI1, it being understood that the spacing of clearances Y32 correspondswith the spacing of rollers y21 and that the subassembly may be placedin such angular position with respect to ring gear I1 that rollers 21are aligned with the clearances 32 before an attempt is made to insertthe subassembly into the ring gear I1.

An understanding of the exact nature of the clutch by which cam sleeve22 is driven is prerequisite to an understanding of the utility of theroller bearing grip clutch consisting of member 23, rollers 21, and ringgear I1, the roller bearing clutch being used in the present inventionas a brake. Shaft Il has secured thereto a driving element 36 of apositive drive single revolution clutch mechanism. The driven element31, which is splined or keyed to sleeve I9, to which cam assembly sleeve22 is secured, is slidably supported upon shaft II, is urged intoengagement with driving element 36 by compression spring 38, and isnormally withheld from engagement with driving element 36 by clutchthrowout lever 38 which cooperates with clutch throwout flange 4I ondriven clutch element 31. Each tooth of both of the clutch elements 36and 31 has one surface substantially in a plane passing through the axisof the shaft and the other surface oblique thereto. Should any torque beapplied to the driven element 31 of the clutch which exceeds the torqueapplied by the driving element 36, the sloping surfaces of the teeth ofone clutch element may tend to slide upon the sloping surfaces of theteeth of the other clutch element, thus shifting driven element 31axially away from driving element 36 and compressing spring 36. If thedifferential between the two torques is appreciable the driven elementmay be rotated ahead of the driving element a distance equal to theextent of several teeth of the clutch member. A torque of suflcientmagnitude to cause driven clutch element 31 to rotate more rapidly thandriving element 36, and thus to gain upon it, may be generated by aheavily biased cam follower riding down a sharply descending slope ofits cam, such as the cam 22, and thus becoming a negative load upon thedriven clutch element 31.

The roller bearing grip clutch hereinbefore described serves as a braketo prevent acceleration of cam assembly sleeve 2l under the influence ofnegative load upon any of its cams. Whenever cam sleeve 2| is stationaryand the gears I6 and I1 are rotating, inner roller bearing clutch member23, which is secured to sleeve I9 and, therefore, directly to camassembly sleeve 2|, is also stationary and the frictional engagementbetween the inner surface of ring gear I1 and rollers 21 tends to movethe rollers into the widest portion of the recesses in which they areseated, the rollers thus being moved substantially free of inner clutchmember 23 so that there is no tendency of gear I1 to impart rotation tothe inner clutch member 23. When cam assembly sleeve 2I is released forrotation `due to the tripping f the clutch by operation of clutchthrowout lever 39 and is rotating at the same speed as gear I1, there isno relative movement between roller bearing clutch member 23 yand ringgear I1 and the springs 26 tend to wedge rollers 21 between the longfaces of the notches in inner clutch member 23, and the inner surface ofgear I1. If

cam sleeve 2| should be subjected to a torque which tends to rotate itfaster than gears I6 and I1, the frictional engagement of rollers 21with member 23 tends to increase the wedging of the rollers betweenmember 23 and gear I1 so that a positive lock between inner rollerbearing clutch member 23 and gear I1 is established and the cam sleeve2l is prevented from accelerating in response to the locally appliedtorque and it is held to the speed of rotation of gears I6 and I1 drivenby shaft I I.

Although specic embodiments of the features of invention have beendisclosed and described herein, it will be understood that the inventionis not limited to such specic embodiments but is capable of modication,reorganization, rearrangement and substitution of parts and elementswithout departing from the spirit of the invention and within the scopeof the appended claims.

What is claimed is:

l. In a roller bearing clutch mechanism including a notched innerelement. a cylindrically apertured outer clutch element having cut awayclearances spaced in accordance with the notching of said inner clutchelement, and spring pressed axially bored rollers disposed between saidinner and outer clutch elements, means for facilitating the assembly ofsaid clutch mechanism including a ring freely rotatable coaxially withand loosely supported upon said inner clutch member, and a plurality ofdepending iingers integral with said ring and spaced therearoundaccording to the spacing of said cut-away clearances of said outerclutch member for receiving and supporting said axially bored rollersand for moving them collectively in opposition to their respectivesprings into registry with -said cutaway clearances, the surfaces ofsaid clearances constituting cam faces for camming the rollers radiallyinwardly in assembling the inner and outer clutch members.

2. In a roller bearing clutch mechanism, van inner `clutch member havinga plurality of notches in the edge thereof, an outer clutch memberhaving an axial aperture proportioned to receive said notched member, aspring pressed axially bored roller disposed in each of the notches forengagement with both of said elements, a retainer ring resting looselyon said notched member and extending partially over said rollers, saidring having depending iingers loosely entering the axial bores in saidrollers, and a plurality of clearance notches formed on the innersurfaces of the outer clutch member constituting cam faces for cammingthe rollers radially linwardly in assembling the inner and outer clutchmembers.

EDWARD S. LARSON.

